Stabilizer for electron tube



April 5, 1955 R. L BoERTzEL 2,705,782

STABILIZER FOR ELECTRON TUBE Filed Feb. 1, 1954 I N! 'E N TOR.

ATTORNEY HUBERT .L- BEIERTZEL United States Patent STABILIZER FOR ELECTRDN TUBE Robert L. Boertzel, Collingswood, N. J., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application February 1, 1954, Serial No. 497,487

Claims. (Cl. 339-93) This invention relates to a stabilizing device for replaceable electric units, and more particularly to a device for clamping an electron tube, or similar plug-in unit against vibration or other movement in any direction.

In equipment which is subject to vibration and which employs tubes or the like which are long in relation to their lateral dimension, special precautions must be taken to protect these tubes against failure due to shock or vibration.

Known clamping devices which have been designed for this purpose have a relatively rigid, elongated member mounted adjacent to and parallel to the tube axis. These devices prevent movement of the tube along the tube axis and in a plane which is defined by the elongated member and the tube axis. However, these devices do not prevent movement in directions perpendicular to the above mentioned plane and, in particular, do not prevent rotational movement of the tube about the elongated member.

The principal object of this invention, therefore, is to provide an improved stabilizing device for electron tubes which will prevent movement of the tube in any direction.

Another object of this invention is to provide a stabilizing device which is adjustable to provide for wide tolerances in the size of the tubes with which the device is to be used.

A further object of this invention is to provide an improved stabilizing device for replaceable electric units which permits rapid replacement of said units and which may be quickly and easily engaged with and released from the units without the use of tools.

A still further object of this invention is to provide an improved stabilizing device for electron tubes which will act to prevent the shorting of an upper tube terminal and possible subsequent damage to the equipment in the event that the contact member should work loose.

A still further object of this invention is to provide an improved stabilizer having means for captivating the tube engaging member so that it cannot become lost in the event that it should work loose.

In accordance with the present invention, the stabilizer comprises a rod which is rigidly mounted adjacent 'to the tube and in parallel relation with. its longitudinal axis, a spring clamping member which grips the rod, and a resilient grommet which is mounted in the clamping member and engages the top of the tube. A portion of the rod is machined to form a relatively rectangular cross-section with two opposing surfaces of the section being grooved or knurled. The clamping member is constructed of a spring metal and is doubled over in the form of a V. Each leg of the V clamping member is provided with a rectangular aperture, one edge of which locks itself in one of the grooves on the rod when the clamping member is urged downwardly against the top of the tube. An extension of one leg is provided with a circular opening to receive the grommet which is composed of a heat-resistant, insulation material. A relatively snug fit between the rectangular aperture in one leg of the contact member and the rectangular portion of the rod prevents rotation of the clamping member about the rod.

The novel features of the present invention, as Well as additional objects and advantages thereof, will be understood more fully from the following description when "ice read in connection with the accompanying drawing, in which:

Figure 1 is a view in side elevation of an electron tube which is being held by a stabilizing device according to the present invention;

Figure 2 is a view in sectional elevation of the rod and a portion of the clamping member as seen from the plane of the line 22 of Figure l in the direction of the appended arrows;

Figure 3 is a plan view in section of the rectangular portion of the rod as seen from the plane of the line 33 of Figure 2 in the direction of the appended arrows; and

Figure 4 is a plan view of the clamping member shown in Figure l in which the upper leg has been broken away.

In the embodiment of the present invention exemplitied in the accompanying drawing, the device is shown, illustratively, for use with an electron tube indicated genrally at 10. The tube 10 includes a base 12, a glass envelope 14, a ceramic cap 16 and a metallic terminal 18. The tube is shown mounted on a chassis 20. The usual socket for the tube is not shown.

The stabilizer assembly consists of a rod 30, a clamping member 50, hereinafter called a spring clamp, and a grommet 70. The rod is rigidly secured to the chassis 20. This may be accomplished, for instance, by means of a screw 22 which enters a tapped hole 32 in the base of the rod. The rod 30 may be made from any of the standard bar stocks such as round, square, hex, and the like, and is shown here as being constructed from round bar stock.

A portion of the upper part of the rod 30 is machined with opposing flats to form a rectangular-like section 34 along which the spring clamp is free to be moved. Figure 3 illustrates a cross-sectional view of the rectangular portion 34 of the rod 30. The machined surfaces are provided with a roughened surface such as knurling or horizontal V-shaped grooves 36 which prevent the spring clamp from slipping when it is assembled on the rod. It will be apparent that this portion 34 of the rod 39 need not have a rectangular cross section. Any type of irregular section, that is, one capable of being engaged by a spring clamp having a complementary aperture so as to prevent relative rotation, will sufiice if the section is further provided with at least two opposing faces having knurled or grooved surfaces.

The uppermost portion 38 of the rod 30 is turned to a diameter which is no greater than the short dimension of the above mentioned rectangular section. This portion is provided so that the spring clamp may be rotated about the rod 30 without removing it therefrom. A fiat washer 49 is provided at the top of the rod and secured by means of a screw 42 which enters a tapped hole 44 in the top of the rod 30.

The spring clamp 50 is made from a spring metal such as heat-treated beryllium copper. Essentially, it is V- shaped spring having one leg approximately three times as long as the other. Both legs of the spring are provided with rectangular shaped apertures adjacent of the vertex of the V. The spring clamp is secured to the rod by means of these apertures. The rectangular aperture 52 in the longer leg 54 is cut to fit closely over the rectanguar portion 34 of the rod to prevent the spring from rotating on the rod. The rectangular aperture 56 in the shorter leg is relatively loose fitting to provide for movement of this leg relative to the longer leg when the spring clamp is fitted on the rod. The longer leg 54 of the spring clamp 50 is provided with a round aperture 58 at the end away from the vertex to receive the grommet 70.

The grommet is made of a resilient material such as Dow-Corning heat-resisting silicone rubber Silastic 250. It is constructed, in the exemplified embodiment, to fit snugly over the ceramic cap 16 of the tube. It tends to absorb shock which is transmitted through the glass envelope of a tube and, in addition, it permits a snug grip on the tube over the tolerance range of its diameter. A feature of the device, in employing a nonconducting grommet, is that it may be employed over a conductive tube terminal or any other projection on the top of the tube to provide a snug grip thereof. Furthermore, if the spring clamp should become loose on the rod, the grommet will prevent damage to the system which might be caused as the result of the tube terminal shorting through the spring clamp.

In placing the spring clarnp St on the rod 30,. or in adjusting it thereon, the two legs are compressed together so that the clamp may slide freely on the rectangular portion 34 of the rod. This rectangular portion is sufiicient in length to accommodate tolerances in tube length permitted in manufacture or even to permit use of the device for different types of tubes. When a tube, or the like, is to be clamped into place, the spring clamp is carried downwardly until the grommet 70 fits snugly over the ceramic cap 16 and the leg 54 is in an essentially horizontal position. The legs are then released and the spring force urges the upper leg upwardly to lock the spring clamp in position on the rod grooves. The V grooves on the rod will prevent longitudinal movements of the spring clamp along the rod and the rectangular apertures in the spring clamp, which are now fitted in locking relation with the rectangular portion of the rod, prevent any rotary motion of the tube about the rod. Hence, the tube is effectively locked against movement in any direction relative to the chassis upon which it is mounted.

When it is desired to release the spring clamp to replace tubes, it is only necessary to again compress the legs and slide the clamp upwardly to the upper portion 38 of the rod. The clamp 50 may then be rotated out of the way of the tube so that it may be easily withdrawn and a new tube put in its place.

The spring clamp will be prevented from sliding offthe rod because of the washer 40 which is attached to the top of the rod and which is provided to prevent the spring clamp from becoming completely separated from the stabilizer. This precludes the spring clamp from becoming lost or perhaps causing damage to the system in which it is used by becoming lodged among connecting wires, terminals, and the like.

What is claimed is:

l. A stabilizing device for an electron tube which is mounted in a plug-in socket comprising a rod rigidly mounted in parallel relation with the longitudinal axis of said tube and socket, a portion of said rod having a substantially rectangular cross section, two opposing faces of said rectangular cross section having a plurality of adjacent V-shaped notches aligned in a direction perpendicular to the axis of said rod, a substantially V- shaped spring clamp having a pair of spaced legs, one V leg of said spring clamp having an opening adapted to fit snugly over the rectangular portion of said rod, the other leg of said spring clamp having an opening adapted to fit loosely over the rectangular portion of said rod, :1 heat resistant, electrically insulating grommet adapted to fit snugly over a top extension of said electron tube, one leg of said spring clamp having an opening for holding said grommet, said rod having a portion of substantially circular cross section whereby said spring clamp may be rotated about said rod, and means at the top of said .rod for preventing removal of said spring clamp.

2. A stabilizing device for an electron tube which is mounted in a plug-in socket comprising, a rod adapted to be rigidlymountcd in parallel relation with the axis of said tube and socket, a portion of said rod having opposed vflats with a plurality of V-shaped notches on the surfaces thereof, a substantially V-shaped spring clamp having a pair of spaced legs, one leg of said spring clamp having an opening adapted to fit snugly over the notched portion of said rod, the other leg of said spring clamp having an opening adapted to fit loosely over the notched portion of said rod, a heat resistant, electrically insulating grommet adapted to fit snugly over a top extension of said electron tube, one leg of said spring clamp having an opening for holding said grommet, said rod having a portion of substantially circular cross section whereby said spring clamp may be rotated about said rod, and means at the top of said rod for preventing removal of said spring clamp.

3. A stabilizing device for a replaceable electric unit comprising a rod rigidly mounted in parallel relation with the longitudinal axis of said unit, a portion of said rod having a substantially rectangular cross section, two opposing surfaces of said section having knurling thereon, a substantially V-shaped spring clamp having a pair of spaced legs, one leg of said spring clamp having an opening adapted to fit snugly over the rectangular portion of said rod, the other leg of said spring clamp having an opening adapted to fit loosely over the rectangular portion of said rod, a heat resistant, electrically insulating grommet adapted to fit snugly over top extension of said electron unit, one leg of said spring clamp having an opening for holding said grommet, said rod having a portion of substantially circular cross section whereby said spring clamp may be rotated about said rod, and means at the top of said rod for preventing removal of said spring clamp.

4. A stabilizing device for a replaceable electric unit comprising a rod rigidly mounted in parallel relation with the longitudinal axis of said unit, a portion of said rod having an irregular cross section, a substantially V- shaped spring clamp having a pair of spaced legs, one leg of said spring clamp having an aperture adapted to fit snugly over the irregular portion of said rod, the other leg of said spring clamp having an aperture adapted to fit loosely over the irregular portion of said rod, an extension of one of'said legs adapted to fit snugly over the top of said unit, and said rod having a portion of substantially circular cross section whereby said spring clamp may be rotated about said rod.-

5. A stabilizing device for electrical units of the type to be plugged into a socket comprising a rod adapted to be rigidly mounted adiacent the socket of said unit, a portion of said rod being provided with opposing flats having knurled surfaces, a substantially V-shaped spring clamp having openings adapted to fit snugly over the knurled portion of said rod, said rod having a portion of substantially circular cross section whereby said spring clamp may be rotated about said rod, and means associated with said spring clamp for gripping the top portion of said electrical unit.

References Cited in the file of this patent UNITED STATES PATENTS Shonnard May 2, 1950 

